Many methods and techniques for manufacturing fire rated doors have been developed over time. But most of these prior art designs do not lend themselves well to fully automated manufacturing processes. Moreover, the prior art fire rated doors are expensive and require the internal mineral core. The internal core can be exposed in routed details and may reduce the strength of the door as a result of the reduced thickness of the door panels. In addition, alignment of the panels during assembly can be troublesome and require additional finishing to square the door after assembly.
Cement-based composites have been used in building materials for many years. For example, U.S. Pat. Nos. 5,549,859, 5,618,341, 5,631,097, 5,641,584, 5,658,624, 5,702,787, 5,766,525, 5,798,151, 5,849,155 and 6379446, and U.S. Published Patent Applications 2008/0099122, 2010/0136269 and 2011/0120349 describe various compositions and processes for making extruded cement-based composite products, all of which are hereby incorporated by reference in their entirety. These patents and published patent applications, however, do not disclose fire resistant composite components having the necessary fire resistant capabilities to produce doors, door cores and building panels that can receive fire rated certifications.